WASHINGTON — It may not be "far more powerful than the aircraft carrier" — as President Trump said in a recent interview, but a well-armed U.S. submarine has arrived in Korea.

The Ohio-class guided-missile submarine Michigan pulled in to the South Korean port of Busan Tuesday for what the U.S. Navy called a "routine visit."  

"During the visit sailors will experience the culture and history of the ROK [Republic of Korea], as well as foster outstanding relations between the U.S. Navy, ROK military and the local Busan community," the U.S. Navy said in a press release.

But the arrival of the Michigan is a significant addition to U.S. naval forces gathering in the Sea of Japan and elsewhere off the Korean Peninsula in response to rising tensions in the area due to a series of ballistic missile tests carried out by North Korea. The aircraft carrier Carl Vinson and its strike group, now accompanied by two Japanese destroyers, also is expected to reach the area in a day or so.

The Michigan may have been what Trump was referring to April 11 when, in an interview with the Fox Business Network, he described US forces heading for the region.

"We are sending an armada, very powerful," Trump told Maria Bartiromo. "We have submarines, very powerful, far more powerful than the aircraft carrier. That I can tell you."

The Michigan is one of four missile and special operations submarines converted from Ohio-class ballistic missile submarines, designated SSGN. While they no longer carry ballistic missiles, the SSGNs carry up to 154 Tomahawk cruise missiles and other weapons and gear in the former ballistic missile tubes.

Perhaps even more significant, the SSGNs can embark up to 66 special operations personnel, who can use the two foremost former missile tubes as lockout chambers to carry out surveillance and clandestine insertion and recovery missions. The submarines are the largest ever built in the U.S. — 560 feet long and displacing 18,750 tons submerged — but they are capable of precise navigation in close waters, a legacy of the highly-capable navigation systems needed for the original ballistic missile mission.

The Michigan arrived fitted with a dry deck shelter, often used to carry swimmer delivery vehicles used by SEALs and other special operations forces.

The SSGNs routinely carry out very long worldwide deployments, often more than a year, with Blue and Gold crews rotating aboard. The Michigan has operated in Korea on several occasions, including a visit to Busan in June 2015.

The Michigan is currently manned by her Blue Crew, commanded by Capt. Joe Turk.

"This crew has displayed incredible professionalism and dedication throughout this deployment," Turk said in the Navy press release. "Every sailor understands the importance of our mission and every one of them is dedicated to ensuring that mission is a success. I simply cannot be more proud of their service.

"We are looking forward to a chance meet up with our ROKN [Republic of Korea Navy] partners and learn about the culture of Korea, for the first time for many of us, myself included," Turk added.

Rear Adm. Brad Cooper, commander of U.S. Naval Forces Korea, called the visit "yet another example of the steadfast ROK and U.S. naval partnership." He noted in the press release that the two navies "work closely with one another every day of the year and this well-deserved port visit is a chance for Michigan sailors to enjoy the wonderful Busan culture that U.S. Navy Korea sailors experience each and every day."